For most automobile owners, there exists a need in the winter for a traction device that will get their car, parked on ice from the curb or driveway, to the middle of the cleared street or to get their car to a main artery of traffic, where the snow and ice has been cleared. The traction device, therefore, should be one in which it is temporary in nature and one in which it is easy to put on and take off.
Snow chains are probably the best device for travelling on snow and ice in a region where there is continuous snow and cold weather. Snow chains, however, have many disadvantages. The first one of which is to predict the weather and time to get to the service station before the snow is too bad. Second, the chains are very cumbersome if you put them on yourself, with only the younger and more rugged bothering with them. Thirdly, they may only be needed on snow and ice for six blocks, but after that one may have six miles to travel on clear paved road. After once on, either of the options is not practical: to take them off is bothersome and to leave them on is bumpy riding.
The studded snow tires of the prior art are unsatisfactory since (1) they stay on for the entire winter during most of which they are unnecessary, (2) they tear up the roads, (3) the studs may tend to make a car slide on a concrete road during hard braking at high speed, and (4) they do not provide a smooth ride.
Other typical prior art traction devices are shown in U.S. Pat. Nos. 4,089,359; 3,935,891; 3,753,456; 3,478,803; 3,249,143; 3,117,612; 3,045,738; 3,132,682; 2,598,851; and 2,443,406. These prior art devices all have in common a cleat or the like parallel to the axis of the wheel and overlying the tire tread. They are either lacking in secure attachment to the wheel by wheel lugs as in the case of U.S. Pat. Nos. 3,249,143 and 3,478,803, or they are attached to the wheel using all of the lugs employed to secure the wheel to the vehicle. These prior art devices are necessarily complex structurally and hence expensive. They are difficult to install and remove.
The traction device of the invention is a simple inexpensive structure which eliminates cleats overlying the tire. The device of the invention is simple to install and remove. Despite the simplified structure of the device of the invention, it is, surprisingly, very effective in providing traction for a vehicle travelling on ice. It is out of contact at all times with the tread of the tire and hence avoids the possibility of it damaging the tread.